Flotation Behavior of Bituminous and Lignite Coals in Salty Water

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High salt concentrations have a significant effect on bulk and interfacial water structure, and colloidal interactions between bubbles and particles hence affect flotation of minerals. In this study, the floatability of Turkish coals in the presence of NaCl, KCl, CaCl2, MgCl2 salts without the use of any flotation chemicals (collector and frother) was investigated in detail. In addition, zeta potential and foam stability tests were performed. The flotation experiments showed that it is possible to float the natural hydrophobic coal in salt solutions in the absence of collector and frother. On the other hand, the flotation of lignite coals is generally difficult. Additionally, MgCl2 and KCl solutions showed the highest and the lowest flotation performance improvements, respectively. The froth stability tests at 1 M salt concentration indicated that there is a correlation between the flotation recovery and froth stability. These results also clearly indicated that Na^+, K^+, Ca^2+, Mg^2+ ions have a strong ion specific effect on the flotation of coal particles.

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Flotation , Coal , Salt , Zeta potential , Froth Stability , Ion , specific effect

Afyon Kocatepe University Journal Of Science an‎d Engineering

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Afyon Kocatepe University Journal Of Science an‎d Engineering